Social foraging can benefit artisanal fishers who interact with wild dolphins

Abstract

Social foraging decisions depend on individual payoffs. However, it is unclear how individual variation in phenotypic and behavioural traits can influence these payoffs, thereby the decisions to forage socially or individually. Here, we studied how individual traits influence foraging tactics of net-casting fishers who interact with wild dolphins. While net-casting is primarily an individual activity, in the traditional fishery with dolphins, fishers can choose between fishing in cooperative groups or solitarily. Our semi-structured interviews with fishers show their social network is mapped onto these foraging tactics. By quantifying the fishers’ catch, we found that fishers in cooperative groups catch more fish per capita than solitary fishers. By quantifying foraging and social traits of fishers, we found that the choice between foraging tactics—and whom to cooperate with—relates to differences in peer reputation and to similarities in number of friends, propensity to fish with relatives, and frequency of interaction with dolphins. These findings indicate different payoffs between foraging tactics and that by choosing the cooperative partner fishers likely access other benefits such as social prestige and embeddedness. These findings reveal the importance of not only material but also non-material benefits of social foraging tactics, which can have implications for the dynamics of this rare fishery. Faced with the current fluctuation in fishing resource availability, the payoffs of both tactics may change, affecting the fishers’ social and foraging decisions, potentially threatening the persistence of this century-old fishery involving humans and wildlife.Significance statementSocial foraging theory proposes that decisions to forage in groups are primarily driven by cost–benefit trade-offs that individuals experience, but it remains unclear whether, and how much, individual foragers’ characteristics influence these trade-offs and consequently the choice to forage in social groups. We study the artisanal net-casting fishers who choose between cooperating with each other or fishing alone when engaging in a rare interaction with wild dolphins. Our findings suggest that cooperative fishers capture more fish than solitary fishers, and that by choosing cooperative partners based on similarities and differences in key social (peer reputation, kinship, friendships) and foraging (fishing frequency) traits; these fishers also experience higher social prestige and more social embeddedness. These results suggest that material gains from foraging—but also non-material benefits accrued from socializing with like-minded individuals—can influence the dynamics of human social foraging.